This disclosure relates to a viscous shear damping strut assembly, and specifically to a damping device with interacting disks for viscous shear to dampen the strut assembly in a mainly linear direction.
Although not limited to the field of use, the damping device may be used with aircraft systems. Certain aircraft systems are used with aircraft jet engines, which are often enclosed by nacelles, a large cylindrical-shaped structure that typically includes one or a pair of pivoting aircraft cowlings. Aircraft engine cowlings are often mounted by hinges to the engine support structure. Latch mechanisms have been used to releasably secure a first aircraft structure, such as an aircraft panel or cowling of an aircraft engine, to another aircraft structure.
Aircraft systems must be able to withstand harsh environments. Aircraft systems must withstand high vibration and extreme temperature and pressure ranges. For example, high pressure seals can break down in such a harsh environment. Damaged seals can cause fluid to leak.
Aircraft also have other special considerations. Space within an aircraft is limited such that components are preferably made as small and compact as possible. Also, weight can affect aircraft design and performance wherein lighter components meeting other desired parameters are preferred. Based on durability, components can be constructed of various materials that may become available.
Viscous shear between disks in a highly viscous fluid (such as silicone) can dampen linear movement. Rotary movement between rotating and relatively fixed (fixed or counter-rotating) disks leads to moderating shear forces of the fluid in the gaps between the disks. Inner friction of a viscous liquid and the surfaces dampens movement.
In this regard, it is desired to have a device for damping linear movement of a strut using principles of viscous shear. This can be used to moderate and smooth movement of opening or closing a panel. Additional features of the disclosure will become apparent upon consideration of the following description of embodiments of the disclosed damping strut assembly.
The present disclosure provides a damping device using viscous shear. The device has a housing with an associated reservoir containing a viscous fluid and one or more movable struts that can extend from and retract into the housing. In one embodiment, the strut has a portion formed as a toothed rack, and an associated axle has a pinion gear on a portion associated with the toothed rack of the strut, wherein teeth of the rack mate with teeth of the pinion gear. A disk or a series of spaced disks can be mounted on the axle inside the reservoir to dampen linear movement of the strut, from shear with a static (i.e. stationary) plate adjacent to the disk on the axle. The spaced disks or plates are adjacent to or interdigitated with the disks on the gear axles to dampen linear movement of a strut.
The exemplification set out herein illustrates embodiments of the disclosure that is not to be construed as limiting the scope of the disclosure in any manner. Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.